Inhibition of Pisum sativum epicotyl elongation by white light – Different effects of light on the mechanical properties of cell walls in the epidermal and inner tissues |
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Authors: | Kensuke Miyamoto Junichi Ueda Takayuki Hoson Seiichiro Kamisaka Yoshio Masuda |
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Institution: | K. Miyamoto and J. Ueda, College of Integrated Arts and Sciences, Univ. of Osaka Prefecture, Mozu-Umemachi, Sakai 591, Japan;Dept of Biology, Faculty of Science, Osaka City Univ., Sumiyoshi-ku, Osaka 558, Japan. |
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Abstract: | White fluorescent light (5 W m?2) inhibited subhook growth in derooted Alaska pea cuttings. In the inner tissue of the subhook, it inhibited the increase in osmotic potential during 18 h incubation. In the epidermis, on the other hand, light did not affect the osmotic potential. Light increased the minimum-stress relaxation time (T0) of the inner tissue cell walls, but did not change T0 of the epidermal cell wall. Light decreased tissue stress determined by the split test and the ability of the inner tissue to extend by water absorption. The short-term light effect on subhook growth. T0, and the tissue stress almost disappeared when pea cuttings were transferred to darkness. These facts suggest that light changes the mechanical properties of the cell wall in the inner tissue of shoots, and decreases tissue stress, which is considered to be the driving force of shoot growth. |
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Keywords: | Cell wall extensibility epidermis inner tissue osmotic potential pea subhook growth photoinhibition Pisum sativum tissue stress |
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